The present invention relates to an angle or position detecting apparatus, a method thereof, a servo apparatus, a servo method, and a motor that allow a substance having mass to be moved to a target position or a target angle in the shortest time.
Conventionally, when a substance having mass is moved for a predetermined distance in the shortest time, the substance is maximally accelerated for the half distance and then maximally decelerated for the rest of the distance. When a substance having mass is rotated, the same method is used. At that point, mass, distance, velocity, acceleration, and target position are substituted with inertia, angle, angular velocity, angular acceleration, and target angle, respectively.
However, in this method, the rotation of the substance is largely affected by the fluctuation of the load or various parameters. Thus, it is very difficult to stop the substance at a target position or a target angle with velocity xe2x80x9c0xe2x80x9d.
When an MR sensor that outputs one wave length of a sine wave or a cosine wave corresponding to one degree of a rotating angle is used, the MR sensor can detect an angle in the step of xc2xc degree.
In addition, most motors are of magnet rotating type.
However, in the case of magnet rotating type motors, when the magnetic field generated by the magnetic circuit is strengthen, the mass (inertia) of the rotating portion of the motor becomes heavy. Thus, although the torque of the motor becomes large, a substance cannot be moved at high speed.
Therefore, an object of the present invention is to provide an angle or position detecting apparatus, a method thereof, a servo apparatus, a servo method, and a motor that allow a substance having mass to be moved to a target position or a target angle in the shortest time.
The present invention is an angle or position detecting apparatus, comprising an actuator composed of a coil and a magnet, a mechanism for performing a rotating operation or a reciprocal operation, a sensor for detecting the angle or position of the actuator and outputting a first sine wave and a second sine wave that are shifted by 90 degrees each other, a counter for storing the current angle or the current position, a memory for outputting a third sine wave and a fourth sine wave that are shifted by 90 degrees each other corresponding to an output of the counter, a first multiplying device for multiplying the first sine wave by the third sine wave, a second multiplying device for multiplying the second sine wave by the fourth sine wave, a subtracting device for subtracting a signal that is output from the first multiplying device from a signal that is output from the second multiplying device, and an operation amplifying means for amplifying a signal that is output from the subtracting device, wherein the current angle or the current position of the counter is increased or decreased corresponding to an output of the operational amplifying means and the increased or decreased angle or position is output as the current angle or current position.
The present invention is an angle or position detecting method, comprising the steps of causing an actuator composed of a coil and a magnet to perform a rotating operation or a reciprocal operation, detecting the angle or position of the actuator and outputting a first sine wave and a second sine wave that are shifted by 90 degrees each other, storing the current angle or the current position, outputting a third sine wave and a fourth sine wave that are shifted by 90 degrees each other corresponding to the current angle or the current position that has been stored, causing a first multiplying device to multiply the first sine wave by the third sine wave, causing a second multiplying device to multiply the second sine wave by the fourth sine wave, causing a subtracting device to subtract a signal that is output from the first multiplying device from a signal that is output from the second multiplying device, causing an operation amplifying means to amplify a signal that is output from the subtracting device, and increasing or decreasing the current angle or the current position corresponding to an output of the operational amplifying means and outputting the increased or decreased angle or position as the current angle or current position.
The present invention is a servo apparatus, comprising an actuator composed of a coil and a magnet, a mechanism for performing a rotating operation or a reciprocal operation, a sensor for detecting the angle or position of the actuator and outputting a first sine wave and a second sine wave that are shifted by 90 degrees each other, a counter for storing the current angle or the current position, a memory for outputting a third sine wave and a fourth sine wave that are shifted by 90 degrees each other corresponding to an output of the counter, a first multiplying device for multiplying the first sine wave by the third sine wave, a second multiplying device for multiplying the second sine wave by the fourth sine wave, a subtracting device for subtracting a signal that is output from the first multiplying device from a signal that is output from the second multiplying device, an operation amplifying means for amplifying a signal that is output from the subtracting device, a model acceleration curve generating means for generating acceleration/deceleration pulses composed of an acceleration and a deceleration, a model velocity curve generating means for generating a velocity data sequence that is obtained by integrating the acceleration/deceleration pulses, a model position curve generating means for generating a position data sequence that is obtained by integrating the velocity data sequence, a means for increasing/decreasing the current angle or current position of the counter corresponding to an output of the operational amplifying means and outputting the increased or decreased angle or position as the current angle or current position, a position error extracting means for extracting a position error from the current angle or current position and the position data sequence, a velocity error extracting means for extracting a velocity error from the current velocity data and the velocity data sequence, the current velocity data being obtained by differentiating the current angle or current velocity, and a feedback loop means for adding the position error and the velocity error, amplifying the added data, and feeding back the amplified data to a driver for driving the actuator, wherein a servo operation of the servo apparatus is performed so that while the servo apparatus is being accelerated or decelerated, the position and the velocity of the servo apparatus do not deviate from a preset position curve and a preset velocity curve.
The present invention is a servo method, comprising the steps of causing an actuator composed of a coil and a magnet to perform a rotating operation or a reciprocal operation, detecting the angle or position of the actuator and outputting a first sine wave and a second sine wave that are shifted by 90 degrees each other, storing the current angle or the current position, outputting a third sine wave and a fourth sine wave that are shifted by 90 degrees each other corresponding to the current angle or current position that has been stored, causing a first multiplying device to multiply the first sine wave by the third sine wave, causing a second multiplying device to multiply the second sine wave by the fourth sine wave, causing a subtracting device to subtract a signal that is output from the first multiplying device from a signal that is output from the second multiplying device, causing an operation amplifying means to amplify a signal that is output from the subtracting device, generating acceleration/deceleration pulses composed of an acceleration and a deceleration, generating a velocity data sequence that is obtained by integrating the acceleration/deceleration pulses, generating a position data sequence that is obtained by integrating the velocity data sequence, increasing/decreasing the current angle or current position of the counter corresponding to an output of the operational amplifying means and outputting the increased or decreased angle or position as the current angle or current position, extracting a position error from the current angle or current position and the position data sequence, extracting a velocity error from the current velocity data and the velocity data sequence, the current velocity data being obtained by differentiating the current angle or current velocity, and forming a feedback loop means for adding the position error and the velocity error, amplifying the added data, and feeding back the amplified data to a driver for driving the actuator, wherein a servo operation is performed so that while accelerated or decelerated, the position and the velocity do not deviate from a preset position curve and a preset velocity curve.
The present invention is a motor, comprising a magnetic circuit having a first ring and a second ring secured on concentric circles, the first ring and the second ring being made of magnetic substances, 2n magnets being disposed on an inner periphery of the first ring and 2n magnets being disposed on an outer periphery of the second ring, the magnetic poles of the 2n magnets disposed on the inner periphery of the first ring being reverse of the magnetic poles of the 2n magnets disposed on the outer periphery of the second ring, and a two-phase or three-phase rotor having two or three coils each having 2n rectangular portions, the two or three coils being adhered so that they are shifted by (180/n) degrees or (120/n) degrees each other, wherein the two or three coils are inserted into the space in which the pair of the 2n magnets are disposed.
The present invention is a motor, comprises a magnetic circuit having a first ring and a second ring composed of magnets, the first ring having a magnetized peripheral surface, the second ring having a magnetized peripheral surface, the magnetic pole of the magnetized peripheral surface of the first ring being reverse of the magnetic pole of the magnetized peripheral surface of the second ring, the magnetized peripheral surface of the first ring and the magnetized peripheral surface of the second ring being oppositely secured, and a two-phase or three-phase rotor having two or three coils each having 2n rectangular portions, the two or three coils being adhered so that they are shifted by (180/n) degrees or (120/n) degrees each other, wherein the two or three coils are inserted into the space between the first ring and the second ring.
The present invention is a motor, comprising a magnetic circuit having a first ring and a second ring, the first ring being made of a magnet, the first ring having a magnetized peripheral surface, the second ring being made of a magnetic substance, the first ring and the second ring being secured on concentric circles, and a two-phase or three-phase rotor having two or three coils each having 2n rectangular portions, the two or three coils being adhered so that they are shifted by (180/n) degrees or (120/n) degrees each other, wherein the two or thee coils are inserted into the space between the first ring and the second ring that are secured.
An angle or a position for which an actuator composed of a coil and a magnet is rotated or reciprocated is detected by a sensor (two-phase MR sensor). The sensor outputs a first sine wave and a second sine wave (signal Vc and signal Vs) that are shifted by 90 degrees each other. A memory (cos ROM) 66 shown in FIG. 4 outputs a third sine wave and a fourth sine wave (signal Vsr and signal Vcr) that are shifted by 90 degrees each other corresponding to the current angle or the current position. The first sine and the third sine wave are multiplexed. The second sine wave and the fourth sine wave are multiplexed. The multiplexed result of the second sine wave and the fourth sine wave is subtracted from the multiplexed result of the first sine wave and the third sine wave. The subtracted result is amplified by an operational amplifying means (zero cross comparator). With the amplified signal, the actuator is driven. As a result, the actuator can be moved to a desired angle or a desired position.